1. Field of the Invention
The present invention relates to a method for manufacturing a waveguide-type semiconductor device.
2. Description of the Related Art
Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2001-127333) discloses a semiconductor photoreceiver formed on a substrate. The semiconductor photoreceiver has a suitable structure for high-speed operation. The semiconductor photoreceiver includes a light-detecting portion formed on the substrate. The light-detecting portion includes an absorption layer that is composed of a semiconductor. The absorption layer receives light and generates a carrier in accordance with the intensity of the light. The semiconductor photoreceiver also includes a waveguide formed on the substrate that is integrated with the light-detecting portion. The waveguide is optically coupled to the light-detecting portion. Light propagating through the waveguide is input to the absorption layer of the light-detecting portion. The light-detecting portion of the semiconductor photoreceiver has a mesa structure having side surfaces that are covered with a semi-insulating semiconductor layer. The mesa structure of the light-detecting portion includes the absorption layer, a p-type layer, and a cap layer. In addition, the light-detecting portion has an electrode formed on the mesa structure. An electric field is applied to the absorption layer of the light-detecting portion through the electrode.
In the semiconductor photoreceiver disclosed in Patent Document 1, a semiconductor layer composed of semi-insulating InP is formed on the side surfaces of the mesa structure of the light-detecting portion.